Energy-efficient adaptive control for cooperative spacecraft rendezvous and docking

An energy-efficient adaptive control is developed for a pursuer spacecraft docking with a cooperative spacecraft. The pursuer spacecraft is subject to parameter uncertainties. A six degree-of-freedom (6-DOF) nonlinear model is expressed by coupled relative attitude and orbit dynamics. In the proposed control, inverse optimality approach is applied, such that the conventional Hamilton-Jacobi-Bellman equation can be avoided, and the controller is energy-efficient. Lyapunov theory is used to prove that the closed-loop systems are asymptotically stable despite of unknown inertial parameters. Numerical simulations demonstrate the effectiveness of our control strategy.